1. Field of the Invention
The invention concerns a heat exchange device, in particular for motor vehicles, and a method of manufacturing it.
It is more particularly concerned with a heat exchange device comprising two separate arrays of heat exchange tubes through which respective different fluids flow.
2. Description of the Prior Art
Publication DE 195 36 116 describes a device of the above kind comprising a row of flat tubes the ends of which are assembled to two tubular header boxes extending parallel to each other. Each of the header boxes is divided internally by at least one partition to define a fluid circuit comprising one subset of the tubes of the array and another fluid circuit comprising another subset of the tubes of the array.
The manufacture of the above prior art device necessitates complex assembly operations, in particular involving brazing. Also, it can be effected only with a single row of tubes, which limits its thermal performance.
One aim of the invention is to overcome the aforementioned disadvantages.
The invention aims in particular to provide a heat exchange device with two arrays of tubes which can be obtained by mechanical assembly operations without any brazing.
The invention proposes a heat exchange device comprising two separate arrays of heat exchange tubes adapted for the flow of different fluids respectively therethrough, and a support plate common to the two arrays and having a first portion with holes to serve as a header for a first array and a second portion with openings for receiving in a forced fit manner the tubes of a second array with curved connectors.
Accordingly the device of the invention combines two heat exchange arrays assembled purely mechanically by means of a support plate which serves simultaneously as the header of a first array and as means for receiving a second array in a forced fit manner.
The above device can be obtained entirely by mechanical assembly, without any brazing, in a single operation.
This results in a compact device that can include one or more rows of tubes.
The tubes of the first array and the tubes of the second array are advantageously parallel to each other.
In one embodiment of the invention the tubes of the first array and the tubes of the second array pass through respective separate first and second sets of fins.
As an alternative to this, the tubes of the first array and the tubes of the second array pass through a common set of fins to constitute a one-piece assembly.
The tubes of the first array are preferably mechanically assembled to the first part of the support plate by means of compressible seals.
In accordance with another feature of the invention the tubes of the first array open into a fluid box having a peripheral edge assembled to the first part of the support plate.
The support plate is advantageously made of a plastics material.
The fluid box can also be made of a plastics material and can then be friction welded to the support plate.
The curved connectors preferably have ends inserted into ends of the tubes of the first array.
In a preferred application of the invention the first array is part of an engine cooling radiator, in particular for a motor vehicle, and the second array is part of a condenser of an air conditioner.
In another aspect the invention comprises a method of manufacturing a heat exchanger comprising the following steps:
a) providing the support plate with curved connectors so that said connectors each have two ends engaged in the crimping openings of the support plate;
b) disposing the tubes of the first array so that their ends face the holes in the support plate;
c) disposing the tubes of the second array so that their ends face the ends of the curved connectors;
d) moving the support plate and the first and second arrays towards each other in a direction parallel to the direction of the tubes so that the ends of the tubes of the first array engage in the holes in the support plate and the ends of the tubes of the second array nest mutually with the curved connectors; and
e) applying a relative thrust between the support plate and the tubes of the second array so as to bring about a forced fit of the ends of the tubes of the second array and of the curved connectors.
The support plate is advantageously provided beforehand with a fluid box adapted to communicate subsequently with the tubes of the first array.
In a preferred embodiment of the invention, in operation d), the ends of the tubes of the first array are inserted into seals surrounding the holes in the support plate.
In another preferred embodiment of the invention, in operation a) and in operation d), the ends of the curved connectors project from one face of the support plate facing towards the first and second arrays so that the nested ends resulting from operation d) are spaced from the forced fit openings. The result of this, in operation e), is that the nested ends are a forced fit in the forced fit openings.
The following description is given by way of example only with reference to the accompanying drawings.